EVALUATION OF EARLY HEMODYNAMIC CHANGES IN CANINE SEPTIC SHOCK MODEL

Abstract

Hemodynamics in septic shock were studied in depth in a canine model used for extracorporeal endotoxin removal studies. Fibrin clots with E. coli (target number of 1.5 × 1010CFU/kg) were implanted in the peritoneal cavity of 9 healthy beagles, (BW: 15–18Kg). Animals received antibiotics and IV fluid (6ml/kg/h). Hemodynamics were compared between survivor and non-survivor groups by 72 hours. The occurrence of 3 distinct hemodynamic phases was confirmed. The 1st phase (0–8h) was characterized by the decrease in cardiac index (CI) and increase in systemic vascular resistance index (SVRI), followed by the 2nd phase (8–24h) with recoveries of CI and SVRI to baselines. It was after 24–72 hours (3rd phase) when hemodynamic conditions known to be typical to sepsis were observed with a high CI and low SVRI. The survival rate was 56%, with one died in the 2nd and 3 in the 3rd phase. In the 1st phase, there was no difference in hemodynamics between the two groups, while significant difference was seen in the 2nd phase in CI, SVRI and PCWP starting at 20 hours after bacterial clot implantation. A decrease in CI (p = 0.02), increase in SVRI (p=0.0l), and a decrease in PCWP (p < 0.01) was significant in the non-survivors, suggesting severer impairment of LV diastolic and systolic function and possible vascular leakage in non-survivors. No difference was noted in blood pressure, CVP, heart rate or body temperature. This study has shown that CI, SVRI 2nd PCWP are the predictors of outcome of sepsis and septic shock. Hemodynamic parameterTable